Performance evaluation of routing and spectrum assignment policies in elastic optical networks

This thesis provides a brief description of optical networks, in order to introduce the reader to the main topic, the elastic optical network (EON) simulator, its features and its new updates like the implementation of the Yen algorithm. This first introduction is important for explaining the physical infrastructure of the simulator, and will follow an order, going from the simplest optical systems to the one simulated plus some details for further implementations. The EON will first be meticulously described by detailing its classes, which model the units that form the network such as nodes, links, spectrum and so forth and then there will be a description of the used allocation algorithms, namely first fit, random fit and longest fit with possible variations in order to have new different allocation strategies and under specific conditions like wavelength/spectrum continuity, spectrum contiguity and wavelength/spectrum non overlapping. After having explained in detail the simulator and the first obtained results, there will be the opportunity for introducing spectrum allocation experiments too, providing results and discussions about what has been observed. There are discussions on real and fictitious network topologies that have been used in order to test the simulator through extreme cases and the allocation algorithms. The final part will treat the implementation of the Yen algorithm in order to update the way the simulator will try to do routing management and to make the foundations for new routing strategies that will reward cheaper paths and/or paths that guarantee fewer converter deployments.